fix(core): Fix binary data helpers (like prepareBinaryData) with task runner (#12259)

packages/core/test/SerializedBuffer.test.ts

@@ -0,0 +1,55 @@
+import type { SerializedBuffer } from '@/SerializedBuffer';
+import { toBuffer, isSerializedBuffer } from '@/SerializedBuffer';
+
+// Mock data for tests
+const validSerializedBuffer: SerializedBuffer = {
+	type: 'Buffer',
+	data: [65, 66, 67], // Corresponds to 'ABC' in ASCII
+};
+
+describe('serializedBufferToBuffer', () => {
+	it('should convert a SerializedBuffer to a Buffer', () => {
+		const buffer = toBuffer(validSerializedBuffer);
+		expect(buffer).toBeInstanceOf(Buffer);
+		expect(buffer.toString()).toBe('ABC');
+	});
+
+	it('should serialize stringified buffer to the same buffer', () => {
+		const serializedBuffer = JSON.stringify(Buffer.from('n8n on the rocks'));
+		const buffer = toBuffer(JSON.parse(serializedBuffer));
+		expect(buffer).toBeInstanceOf(Buffer);
+		expect(buffer.toString()).toBe('n8n on the rocks');
+	});
+});
+
+describe('isSerializedBuffer', () => {
+	it('should return true for a valid SerializedBuffer', () => {
+		expect(isSerializedBuffer(validSerializedBuffer)).toBe(true);
+	});
+
+	test.each([
+		[{ data: [1, 2, 3] }],
+		[{ data: [1, 2, 256] }],
+		[{ type: 'Buffer', data: 'notAnArray' }],
+		[{ data: 42 }],
+		[{ data: 'test' }],
+		[{ data: true }],
+		[null],
+		[undefined],
+		[42],
+		[{}],
+	])('should return false for %s', (value) => {
+		expect(isSerializedBuffer(value)).toBe(false);
+	});
+});
+
+describe('Integration: serializedBufferToBuffer and isSerializedBuffer', () => {
+	it('should correctly validate and convert a SerializedBuffer', () => {
+		if (isSerializedBuffer(validSerializedBuffer)) {
+			const buffer = toBuffer(validSerializedBuffer);
+			expect(buffer.toString()).toBe('ABC');
+		} else {
+			fail('Expected validSerializedBuffer to be a SerializedBuffer');
+		}
+	});
+});